Ferroelectric domain reconfiguration contributions to bulk photovoltaic effect in LuMnO3

Bulk photovoltaic effect (BPE), occurring in non-centrosymmetric materials, lead to a characteristic dependence of the short circuit photocurrent (JSC) and open circuit voltage (VOC), that oscillate when changing the light polarization. In ferroelectrics, the switchable nature of the polar domains implies that JSC and VOC may be dependent on the polarization direction. Therefore, BPE could constitute a tool to explore ferroelectric polarization switching dynamics. We shall report on the BPE measurements in ferroelectric hexagonal LuMnO3 single crystals and thin films. It will be shown the JSC oscillates in agreement with the crystal class symmetry of the compound. However, the amplitude of the measured oscillations is found to be largely affected by polarization back-switching occurring in presence on imprint or related electric fields. As a practical consequence, evaluation of the Glass tensor elements characterizing the BPE response and thus comparison to theoretical predictions is challenged.